Hi i just purchased a 06 iq440 last week. The chaincase was busted so i am in the process of replacing it. I got the parts today and am just wondering what purpose the carriage screw serves?

if you look at the parts list diagram at the polaris web sight it shows 2 carriage bolts. they come in from the back and fasten with nuts on the front of the case.

No, i believe you are referring to the carriage bolt. What i am talking about is the Carriage screw. It is on the chaincase parts diagram. PN:7515477

It seems to just go through the middle of the case from the backide fastened with a nut on the inside. But i don't see any purpose it serves.

That screw is just used to plug the hole in the case.

The IQ chaincase is the same as many earlier ProX and other cases. Many of those cases had a longer carriage screw and it went all the way through the outer cover. The IQ uses a different style cover and does not need the longer screw. So they put a small one in it with a Nylock nut to hold it in place.

So to answer your question, on the IQ chaincase, the screw does nothing except plug the hole in the case.

Ok thank you. I was thinking that it might just be there to fill the hole but i wanted to make sure. Also the previous owner had a 5/8 inch 45 tooth bottom gear with the 3/4 inch 19 tooth top. I went to reinstall and noticed that the chain will rub on the bottom of the case. Should i purchase the 3/4 inch bottom gear to fix this problem?

Your '06 sled likely has a 3/4" bottom gear and the 7/8" top gear. 13 wide bottom and 15 wide top is what they are sometimes referred to by Polaris. There is no such thing as a 15 wide bottom gear so you have to stay with the one you have. Rubbing on the case cover is pretty normal for an '05 & '06 IQ. You should just keep the chain and gears you have and change the oil fairly often. If you decide to regear the sled you can consider the 13 wide (3/4") top gear, bottom gear and chain as long as you don't plan to SnoX the sled. If Snox is your plan you should use the slip gear and the 7/8" wide chain and top gear if you plan to jump the sled quite a bit.

Just normal, hard trail riding you are ok with the 3/4" wide stuff and no slip gear.

There is lots of info here discussing the '06 chaincase and lower bearing issues. Make sure you have the self alligning bearing in your case. HEre is just one af several threads that discusses this bearing.

Self Alligning Bearing IQ 440

here are a bunch more

I measured again and the bottom measures 5/8 and the top measures 3/4. The chain measures 7/8. I already purchased the self aligning bearing so that is taken care of.

So does the top gear slop side to side in the 7/8" wide chain or is there little to no side to side clearance between the top gear and the chain? If you have a 7/8" wide chain and the top gear fits nicely with little or no side to side clearance then thats a 7/8" wide top gear. No matter what it actually measures. In other words, would the next wider (7/8") top gear fit inside the chain?

To be sure what chain you actually have you should count the links it takes to make up it's width. A chain with 15 pieces in the link is a 7/8" wide chain. A chain with 13 pieces in a link is a 3/4" wide chain.

Do you have the slip gear on bottom? Slip Gears only came in 3/4" wide for that sled.

If you have lots of side to side clearance between the top gear and the chain you have a mismatched set of chain and gears and you will have to decide whats best for your application. Are you SnoX racing the sled or trail riding it?

Don't mean to lead you astray here but I have a feeling you have a completely stock chain and gear set here. In a stock '06 IQ the top gear fit nicely into the chain and the bottom gear has plenty of side to side movement. And the bottom of the chain rubs on the case cover.

Maybe its best I stay out of this one, however I brought my sled over to Kingxp's house today to install my headlights and come to find out I am missing my high beam low beam switch, so my lights dont come on at all.

He showed me his top and bottom gear and the bottom gear was definately not as wide, he also pointed out the rubbing marks he had in his chaincase.

Sounds to me like it's stock and perfectly normal.

You can jumper out your hi/low switch if you don't want to buy one. Very simple.

We didnt see why someone would replace it with a different gear in the first place. Im sure they are the stock gears then.

Could you elaborate ? If I can get away with not ordering a switch then I wont do it. Will my lights be on permanent low beam or high ? The reason why we found that out was because we took the switch of his and plugged it into mine. At first we thought I might need my tach to be hooked up to complete the circuit or something

For Low Beam connect the Yellow wire to the Dark Green.

For High Beam connect the Yellow wire to the Yellow/Red.

And your lights will be on permanitely which ever way you hook them up.

I would go with High Beam if it were mine.

Yes the top gear has some slop but a 7/8 should fit. Its the bottom one i was concerned with since there is a 1/4 inch of play in it but it sounds like thats normal.

The chain is the 7/8 with 15 pieces.

No i dont have the slip gear and i plan to trail/ditch ride.

The chain doesnt have a slight rub, it binds on the bottom inside of the case. I started to torque it down and realized that it was pressed against the case so tight i couldn't spin it. Is there suppose to be any spacers on the bottom or something?

Binding on the inside??? Thats definately not normal. There are not supposed to be any spacers behind the bottom gear. It sounds like the drive axle is not coming through the chaincase all the way. Can you see from the inside of the tunnel that the Hex on the axle is almost touching the seal. Thats the way it should be.

Torque on the bottom gear bolt must be 19 ft/lbs. No More.

I have never seen a chain and gears bind or rub on the chain case, just the cover.

Did you just take this apart for maintenance and now you are putting it all back together? Or was there something wrong when you took everything apart. You might not have the chaincase or drive axle quite in the right spot yet.

Nothing should rub or bind except the chain on the cover at the very bottom just a little.

I know, when i went to tighten the bottom gear the chain was pressed right up against the inside of the case on the bottom where the case rises up next to the drain plug. Yes the hex is right up to the seal. Wickedgmc's sled is in my garage right now to compare to and they both are at the seal.

I bought the sled with the chaincase out of it and in pieces. The previous owner broke the chain last race season and it caused some destruction to the case so it needed to be replaced. That bottom gear measures 5/8. If i ordered a 3/4 gear would that make make a difference?

If nothing else I suppose we could take the cover off wickedgmc's sled and look at it for comparison.

The first picture is of the bottom gear on the 7/8 chain pushed all the way to the back side so you can see how much space there is.

The second picture is of top gear pushed all the way to the back side of the chain.

This is the picture of the old case but you can see where the rub marks are. This is the same place it is binding on my new case.

Your chain and gears are stock, thats exactly what they are supposed to look like. The pic of the damaged chaincase also looks fairly normal. If the chain breaks a link before it comes completely apart it make marks like that. If the chain breaks under a load it will leave marks like that. That is a fairly normal looking chaincase for a race sled that may have broken a chain.

How about your chain adjuster, is it in place and most of the slack out of the chain when you torque the lower bolt? If the chain is loose it could easily bind up on the exact area yours is binding when you torque the lower gear in place. Slip the adjuster in place and run the adjuster screw in most of the way, see if the chain tightens up on the lower sproket and is no longer rubbing on the case.

I think you are very close. But it's better to check everything over and ask questions than damage another chaincase.

Good Luck

Tom you were right! All I had to do was put some tension on the chain and that made the chain just rub a little. Do you have any tips for aligning the skid so it can be bolted back in?

Good Work

I do not loosen the rear axle when I remove skids but it may be too late for that.

When I install the skid I put the rear of the skid in the track first. I also have the two front bushings not in the Front Torque Arm. I have them all greased up but not installed in the arm. I use a 5/8" standard length socket with a wobbly extension and make sure I have at lease 10" of extension (for the rear two bolts). Of course the torsion springs are unsprung and loose.

Here is my technique, it's easier with two people but one will also work. There are a couple of steps that you need a second set of hands if you haven't installed a skid at least 40 times. LOL.

1. Tip the sled up on its side, I rest the handlebars on a standard height 5 gallon paint bucket. Shorter if you have wider than stock bars.
2. Pull the track out till it is 45* from the chassis.
3. Install the skid rear axle first, pay close attention to the torsion springs and don't allow them to get caught on the wrong side of the rear axle wheels. You will need to keep an eye on these untill you get the rear of the skid bolted in.
4. With the skid properly aligned with the track, stuf the front arm up into the tunnel.
5. Align the front torque arm bushing hole with the hole in the chassis. The upper side, the one you can see from the running baord side.
6. When you get the hole sorta lined up, drop the bolt into place, and push the bolt all the way down till it's flush with the chassis.
7. Install the front bushing, it will try to push the bolt back out and you will have to keep the bolt pushed down. If you don't have help you can balance/jiggle the skid with your foot and use both hands to install the bushing and hold the bolt down.
8. If you are alone. Install the bushing on the other side of the Front Torque Arm and install the bolt backwards from the inside out. You will be swapping ends with this bolt when you flip the sled over.
9. If you have help do not install the bushing into the FTA yet. Ask your helper to insert the bolt from the under side while you align the hole in the chassis with the FTA hole. Once they get the bolt in place have them hold the bolt there by keeping pressure on it. Install the bushing using the bolt to help you line every thing up, you will need to jiggle and work the skid around to get the bushing to go into place.
10 Install both nuts if you haven't already done it, you can tighten them now if you like.
11. Push the skid up into the tunnel. Many times you have to spread the tunnel by standing on the bottom inside and reefing up on the top side.
12. Once you get the Rear Torque Arm up into the tunnel you need to be prepared with the 5/8" socket and the wobbly extension and ratchet.
This step works best if you have help but you can do it alone with practice.
13. Collapse the skid some and push the idler wheel forward and back till the threaded nut lines up with the hole.
14. When the nut and hole line up install the bolt using the wabbly extension. The wobbly works good because it puts the correct angle on the bolt as you are trying to screw it in. Tighten the bolt up all the way.
15. Flip the sled on the other side using the bucket to hold the bars up.
16. If you haven't already got the FTA bolt in the proper orientation then you must push the bolt out and put it in from the running board side now.
17. Allign the RTA nut and install the bolt using the wobbly extension and socket.
18. Tighten all the bolts pretty tight, about all you can with a normal 3/8 drive ratchet. Don't get crazy just get them good and tight.
19. Put the two torsion springs back on the perches and flop her down on all fours.
20. Allign/adjust the track and tighten the rear axle.


Whew....bet you guys thought I'd never quit.

Good luck.

Thanks for the tips Tom. I finished putting it all together last night. I ended up using a come along and chain to pull the skid into a position where the rear bolts lined up. Then I attached the torsion springs which made the front line up within a quarter inch of the hole. I was then able to use a screw driver on one side to pry it into position and put the front bolts in. This only took me a half hour by myself and it was fairly easy.